Many water sources that are used by consumers for personal care contain elevated levels of calcium and magnesium salts, as well as undesirable levels of redox metals salts. As such, using chelants to sequester trace redox metals often proves to be ineffective because most chelants also competitively bind calcium and/or magnesium.
It has been found that even trace quantities of copper can deposit on the hair surface and in between the cuticle layers of hair. This deposition of copper on hair is especially problematic because transition metal ions, such as copper and iron, can facilitate reduction-oxidation (redox) reactions during hair coloring treatments and during UV exposure. These reactions generate reactive oxygen species (ROS), which in turn can cause damage to the hair. In addition, they can interfere with the oxidative color formation chemistry and lead to reduced color uptake for hair colorant users.
Accordingly, there is a need for an improved hair care regimen that can inhibit copper deposition on hair, as well as facilitate the removal of copper already deposited thereon.
Consumers use a variety of hair care products for their personal hygiene and improved appearance. Shampoo products are routinely used daily (or less frequently) by many consumers to clean their hair. Shampoos contain detersive surfactants that remove sebum, dirt and other residues from hair after water rinsing. Many of these consumers apply rinse-off hair conditioners in a separate step after shampoo washing to achieve better combability, hair damage repair, hair damage protection, hair feel and appearance. Hair conditioners typically contain silicones, organic oils, cationic surfactants or other hydrophobic conditioning agents that are deposited on hair surfaces and provide these benefits. Other consumers also use leave-on-treatments, after the application and rinsing of the shampoo and the rinse-off conditioners, for additional or more effective conditioning benefits.
Hair bleaching and colorant products are also commonly used today to provide a better hair appearance. Most specifically, hair bleaching compositions contain oxidizing agents in an alkali solution. They are used to oxidize the natural hair melanin and their use results in lighter colored hair.
Oxidizing agents are also used during oxidative dyeing treatments, which represent the most commonly used hair colorants. Coloring consumers typically dye their hair using such products every 6-8 weeks.
Application of permanent dyeing or bleaching compositions result in some hair fiber damage, making consumers' hair more hydrophilic, difficult to comb, more porous and feeling less soft than undamaged hair. For that reason, these compositions are typically sold as a kit along with a rinse-off conditioner. This rinse-off conditioner is applied on the hair after the bleaching or dyeing composition has been rinsed off. Typically, such “in-box” conditioners contain higher concentration of silicone or other conditioning agents and result in more effective hair conditioning than the typical routine conditioners that consumers use after their routine shampoo. Some consumers use such “in-box” conditioners more frequently than their 6-8 weeks hair coloring for more effective hair conditioning. A possible frequency of using “in-box” rinse-off conditioner is every 1-2 weeks. It was surprisingly found that the use of combinations of hair care products that contain varying types and levels of chelants is able to remove copper salts from hair significantly more effectively, providing protection from hair damage caused by UV and contributing to hair health, in particular when an oxidative hair dye is used.